A yellow weather warning for high temperatures remains in force on Wednesday, the met service said.
Initially issued at 6pm on Tuesday, the yellow alert will continue to be in force until 4pm on Wednesday.
Temperatures will reach approximately 41C inland, and average from 27 to 35C in the mountains, depending on altitude, KitasWeather wrote.
Minimum night-time temperatures are not expected to drop below 25 to 27C inland and around the coasts.
Click here to change your cookie preferences